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This invention relates generally to film processing, and more particularly, to a low-cost system for developing x-ray films on a semi automated basis. While the invention is described in particular reference to its use for x-ray film development, those skilled in the art will recognize the wider applicability from the principals disclosed hereinafter.
Table-top automatic x-ray film processors often are used in individual offices of dentists, doctors and chiropractors, for example, to develop films taken of patients under treatment. Conversely, floor-standing automatic x-ray film processors are normally used in hospitals, where higher-volume film processing is required. In general, a body of art has developed around automatic film processors that utilize heated liquid chemicals in order to develop the film. As used herein, heated liquid chemicals refer to developer solutions, for example, which are specifically formulated for use in automatic x-ray film processors and which are normally utilized within a temperature range of 89 to 96 degrees Fahrenheit. These automatic x-ray film processors require heaters for the developer chemistry and often include automatic replenishment systems, recirculation systems and process control systems to bring developer chemistry to operating temperature, and maintain temperatures at specific levels, within a narrow range, over long time periods. Because the developer chemistry must be heated to a relatively high temperature, there is a considerable warm-up period required before the processor may be utilized to develop films.
Existing tabletop automatic film processors generally require 15 amp electrical service (10 amps at minimum) to operate their heaters and associated equipment, and generally require permanent plumbing connections for proper operation. Existing tabletop processors generally incorporate a xe2x80x9cshallow tankxe2x80x9d design, to minimize manufacturing costs, and accordingly, generally require recirculation and replenishment systems, because of the limited liquid volume in each tank. For the purpose of this specification, xe2x80x9cshallow tankxe2x80x9d refers to tanks, which when filled with liquid to operating levels while containing a transport rack, generally contain liquid with a depth of four (4) inches or less and generally having liquid volumes of one (1) gallon or less per tank.
Because of the costs associated with meeting these various operating requirements, and because of the costs of purchasing, installing and maintaining tabletop automatic film processors, many potential customers have been unable to justify the cost of purchasing such tabletop automatic film processors, particularly if their daily film usage is low. Consequently, these potential customers have continued to utilize hand tanks (trays) and manual hand dipping and air-drying in order to obtain dry, fully developed films. While xe2x80x9chand-tankxe2x80x9d development produces acceptable films, the use of open chemical tanks or trays in a medical or medical-like environment is undesirable. In addition, there is no convenient way for an operator to tell when the chemicals in use should be replenished or replaced.
We have devised a low-cost, automated film processing system which can economically replace the existing hand-dipping development of films, but which is also later expandable in field, to accommodate additional features, should the owner wish to upgrade the capabilities of the processor.
One of the objects of this invention is to provide a low-cost automated tabletop film processor.
Another object of this invention is to provide a low-cost, automated table-top film processor having an enclosure and internal structures which are designed to accommodate the in-field installation of upgradeable features for the system easily, at any later date.
Another object of this invention is to provide a low-cost, automated, easily-upgradeable-in-field tabletop film processor, which provides for the development of x-ray film at room temperatures, without heated chemistry or a heated dryer.
Another object of this invention is to provide a low-cost, automated, easily-upgradeable-in-field table-top film developer system which does not require heated chemicals nor a heated dryer nor recirculation mechanisms nor automated replenishment systems nor external plumbing for operation, but which is capable of easy in the field upgrading to include one or more of the above features.
Other objects will be apparent to those skilled in the art in light of the following description and accompanying drawings.
In accordance with this invention, a low-cost table-top x-ray film processor capable of being easily-upgradeable in the field at a later date, by incorporating internal component placement at predetermined locations within the processor is provided. In the preferred embodiment a first tank for containing developer solution, a second tank for containing a fixer solution, and a third tank for containing wash water are used. Preferably, each of the tanks is substantially deeper than normally required for film processing. The chemistry employed in the embodiment illustrated is chosen so as to enable the processor to operate for long periods at room temperature. A dryer section incorporating air blowers but with no air-heating or film-heating elements also is provided. A transport rack drive system for advancing film through the first, second and third tanks and thru the dryer section is operated by a variable speed motor operably connected to the transport rack drive system. Motor speed adjustments adjust the time required to process film through the tanks and dryer, and provides compensation for degradation of the chemical composition of the fixer and developer solutions, variations in ambient room temperature, and; differing density requirements for film processing.